Some say the Greenbacks were what got Lincoln shot.
Take a look at the United States Notes released in 1963 before Kennedy was shot.
http://cgi.ebay.com/1963-XF-Condition-5-United-States-Note-Red-Seal_W0QQitemZ300375266871QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45efc2d637
One of LBJs first acts was to take the United States Notes out of circulation.
http://www.john-f-kennedy.net/thefederalreserve.htm
That link is for those tolerant of conspiracy theories.
I'm aware of that as well. I just don't see the difference between pieces of paper printed by the mint and pieces of paper printed by a bank, other than the fact that theoretcally (and please notice that I said theoretically) the bank has "real money" on hand to cover the paper while the mint doesn't.